Well, not the only downside. Wen edit button?
The mint could go down. This is why people will form a social reputation layer around which mints are trustworthy. I think this is a better scaling solution than a lightning based reputation layer.
Discussion
With regard to ecash, it's certainly a cool product, but I think it's a pale imitation of an asynchronous payment. Let's say Alice wants to send money to Bob. If Alice uses Carol's service to create an ecash token for Bob, it might seem asynchronous because Alice may go offline. But Alice isn't really the sender anymore. She gave her money to Carol and got her to promise *she* will send it to Bob. (Or rather, whoever comes first to claim it with something that is essentially a promissory note.) When that happens, the real sender is not Alice, it's Carol, and in order for it work Carol (the sender) must be online when Bob wants the money.
I don't have anything against that, I think it's cool. But I don't think it's *as* cool as a true asynchronous payment. With zaplocker, Carol never has your money. Carol is essentially a routing node between Alice and Bob, and routing nodes don't have custody of funds that use them as part of a path. I think that's cooler than a custodial model like ecash. Instead of depositing *money* with Carol, Alice routes a payment *through* Carol in such a way that Carol can only cancel it or forward it, not keep it. But after that it's largely the same: Alice may go offline, and Bob may come collect his money at his leisure. With ecash, Bob doesn't have a time limit, which is cool, but I think that's an acceptable tradeoff since the gain is self custody.
Until we have drivechains, this obsession with making everything non-custodial just seems silly (arguably it's silly in a drivechains world too if you consider funds in the drivechains under the "custody" of the miners).
The fact is that custody scales payments. For small transactions, like zaps, it's probably fine to have a custodian. Obviously it would better to just run a lightning node, but I think custody is better than stuck htlcs.
just my 2 sats
You make a compelling argument about charging for the use of HTLCs. There's definitely some protocol work to enable this use case more widely.
I think with the rising price of bitcoin the value of payments on LN will increase and there will be a use for non-custodial async payments. It is super niche today but will become more necessary in time. So thank you for pushing the tech forward. I also think there will always be demand for custodial payments that have to make less engineering trade-offs and can deliver a better UX. This is a much much bigger market IMO.
What *I* find cool is imagining how to scale up privacy tech to the rest of humanity who are (let's be honest) never gonna give a shit about the cypherpunk ideals of bitcoin. I want to offboard enough people from fiat to degrade and destroy that system and move the whole world to a better system. I think ecash is perhaps the most promising new tech in this regard. I am keenly watching the development of covenants and payment pool proposals. If that effort goes well it could obsolete a lot of what we're talking about in this thread.